Design Example Report

Transcription

1 Design Example Report Title Specification Application Author Document Number 2.2W Charger using LNK501P Input: Vac Output: 5.5V / 0.4A Cell Phone Charger Applications Department DER-13 Date February 4, 2004 Revision 1.0 Summary and Features Uses an EF12.6 transformer No Y1 capacitor Meets CISPR-22B No optocoupler Low component count Very low earth leakage current The products and applications illustrated herein (including circuits external to the products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to. A complete list of patents may be found at Hellyer Avenue, San Jose, CA USA. Applications Hotline:

2 Table Of Contents 1 Introduction Power Supply Specification Schematic PCB Layout Bill of Materials Transformer Transformer Winding Electrical Specifications Transformer Construction Winding Instructions Materials Design Notes Performance Data Line and Load Regulation Efficiency No-Load Input Power Thermal Measurement of Critical Parts Waveforms Drain Voltage and Current Output Voltage Start-up Profile Load Transient Response (0.2 A to 0.4 A Load Step) Output Ripple Measurement Ripple Measurement Technique Output Voltage Ripple EMI Tests CSPR22B at 230 Vac CSPR22B at 115 Vac Revision History...21 Important Notes: Although this board is designed to satisfy safety isolation requirements, the engineering prototype has not been agency approved. Therefore, all testing should be performed using an isolation transformer to provide the AC input to the prototype board. Design Reports contain a power supply design specification, schematic, bill of materials, and transformer documentation. Performance data and typical operation characteristics are included. Typically only a single prototype has been built. Page 2 of 23

3 1 Introduction This document is an engineering report giving performance characteristics of a 2.2W charger/adapter. The supply uses LinkSwitch an integrated IC combining a 700V high voltage MOSFET, PWM controller, start-up, thermal shutdown, and fault protection circuitry. This document contains the power supply specification, schematic, bill of materials, transformer documentation, and performance data. Page 3 of 23

4 2 Power Supply Specification Description Symbol Min Typ Max Units Comment Input Voltage V IN Vac 2 Wire- No protective ground Frequency f LINE 47 50/60 64 Hz No-load Input Power (230Vac) 0.3 W Output Output Voltage 1 V OUT 5.5 V see Figure 1 Output Current 1 I OUT 0.4 A see Figure 1 Continuous Output Power P OUT 2.2 W Efficiency η 67 % At full 230V Operating Temperature T AMB C Conducted EMI CISP22B/EN55022B with Artificial hand connected to output return Table 1 Power Supply Specification V-I CHARACTERISTIC HLIMIT LLIMIT 6 Vout Iload Figure 1: Output V-I Characteristic Envelope Specification Page 4 of 23

5 J VAC J1-2 RF1 10 Ohm 2W 3 Schematic D1,D2,D3,D4 1N4005 L1 1mH C2 4.7uF + 400V C1 4.7uF 400V + D C R1 23.7K 1% U1 LNK501 S 143T #37 11T #36 x4 C3 0.22uF 0603 C4 0.1uF, 100V D5 1N4937 R2 130R 1% * T1 * 5 3 * 6 EF12.6 Lp=2.5mH 18T #32 TIW D6 UG1B + C5 330uF 10V R5 J2-1 56K 0603 J2-2 Figure 2: Schematic diagram R_CABLE 0.2 R_LOAD 12 R_INT RES 0.5 D2 1N4001 D1 1N4001 C1 1000uF Figure 3: Typical Battery Model Note: The LinkSwitch is designed for a battery load (see model in Figure 3). If a resistive or electronic load is used, the supply may fail to start up at full load. This is normal. If startup is needed into a resistive load, increase C3 to 1uF. Page 5 of 23

6 4 PCB Layout Figure 4: PCB Layout and Dimensions (0.001 inch) Page 6 of 23

7 5 Bill of Materials Item Quantity Reference Part Description 1 2 C1, C2 4.7uF, 400V 2 1 C3 0.22uF, 25V,Y5V, 0603 SMD ceramic 3 1 C4 0.1uF, 100V, X7R ceramic 4 1 C5 330uF, 10V Low ESR E-cap Panasonic FC series 5 4 D1, D2, D3, D4 1N4005, 1A, 600V 6 1 D5 1N4937, 1A, 600V 200nS, Fast Rectifier 7 1 D6 UG1B, 1A, 100V, 15nS Ultra Fast Rectifier 8 1 L1 1mH Inductor- Tokin part #SBCP-47HY102B 9 1 RF1 10 ohm, 2W, Fusible- Vitrohm Series 10 1 R2 130 ohms, 1% 0603 SMD resistor 11 1 R ohm 1%; 1/4W resistor 12 1 R5 56 ohm; 0603 SMD resistor 3 1 T1 Custom EF12.6 Core & Bobbin 14 1 U1 LINK501P- High Voltage IC; Power Integrations, Inc 15 1 PCB FR1 1oz copper DIM: 1.7 x 1.1 ; 1.0mm thick Page 7 of 23

8 6 Transformer 6.1 Transformer Winding 1 WDG3 133T 37AWG 5 WDG1 18T 32AWG T.I.W WDG2 11T 4 x 36AWG 3 Figure 5 Transformer Schematic EF Electrical Specifications Electrical Strength Primary Inductance (Pin 1 -Pin 42KHZ Primary Leakage 60Hz 1minute, from Pins 1-3 to Pins 5-6 All windings open L K with pins 5-6 shorted 3 kv for 1 minute 2450 uh 2700uH < 60 uh Page 8 of 23

9 6.3 Transformer Construction 1 4 WDG WDG2 WDG1 Figure 6 Transformer Cross-section EF Winding Instructions Place the bobbin on the winding machine with pins 1-4 on the right side. Winding should be in forward direction. WDG1: Secondary Winding Start at pin 4 temporarily. Wind 18 turns of item 5 from right to left with tight tension. Wind uniformly in a single layer across entire width of bobbin. Finish on pin 6. Basic Insulation Secure winding partially using item 6. WDG1: Secondary Winding Basic Insulation WDG2: Cancellation Winding Basic Insulation Change the start pin connection of secondary winding from pin 4 to pin 5. Continue winding the tape previously placed for one layer with overlap to secure the end wire of WDG1. Start at pin 3. Wind 11 turns with quadfilar of item 3 from right to left with tight tension. Wind uniformly in a single layer across entire width of bobbin. Finish on pin 4. 1 layer of tape (Item 6) for insulation. Page 9 of 23

10 WDG3: Primary winding 3 layers. Start at pin 4. Wind 143 turns of item 4 from right to left in three layers across entire width of bobbin. Wind uniformly all layers with tight tension. Finish on pin 1. Outer Insulation 10 Layer of tape using item 7. Core Assembly Assemble and secure core halves with glue. Shield / Belly Bans Crop unused pins Remove pin 7 and Materials Place outside 1 turn of item 8 with tight contact to winding surface. Connect item 8 to pin 3 by item 3. Item Description [1] Core: EF12.6 [2] Bobbin: BEF12.6- Horizontal 8-PINS [3] Magnet Wire: #36 AWG [4] Magnet Wire: #37 AWG [5] Triple Insulated wire: # 32 AWG [6] Tape: 3M 1298 Polyester Film (white) x 2 mils [7] Tape: 3M 1298 Polyester Film (white) x 2 mils [8] Copper Foil: 0.01mils x 6mm [9] Varnish 6.6 Design Notes Device Frequency of Operation Mode Peak current Reflected Voltage (Secondary to Primary) AC Input Voltage Range LNK501P 42KHZ Discontinuous A 47 V VAC Page 10 of 23

11 7 Performance Data Measurements were done at room temperature unless otherwise specified. 7.1 Line and Load Regulation V-I CHARACTERISTIC HLIMIT LLIMIT 115V 230V Vout Iload Figure 7 Output VI Characteristic at selected input voltages (115V & 230V) V-I CHARACTERISTIC V 265V HLIMIT LLIMIT Vout Iload Figure 8 Output VI Characteristic at selected input voltages (90V & 265V) Page 11 of 23

12 7.2 Efficiency The efficiency was measured at max power (~6.4V, 0.4A), using a 16Ω resistor, at room temperature. EFFICIENCY CHARACTERISTIC EFF (%) 60 Eff VIN (VAC) Figure 9 Efficiency vs. Input voltage Page 12 of 23

13 7.3 No-Load Input Power NO LOAD CHARACTERISTIC Pin (mw) Pin Vin (VAC) Figure 10 Zero load input power vs. Input line voltage 7.4 Thermal Measurement of Critical Parts Measurement was done with a 16Ω resistor load, (~6.4 V, 0.4A) inside a plastic enclosure at 25 o C with no airflow. Reference Description Temperature U1 LNK501P 65ºC T1 EF12.6 Transformer 58ºC D6 UG1B 69ºC Page 13 of 23

14 8 Waveforms 8.1 Drain Voltage and Current Figure 11 Linkswitch (U1) Vdrain and I drain Waveform. Vin=90Vac, Full load; CH3: Vdrain (100V/DIV); CH1: Idrain (0.1A/DIV) Figure 12 Linkswitch (U1) Vdrain and I drain Waveform. Vin=265Vac, Full load; CH3: Vdrain (100V/DIV); CH1: Idrain (0.1A/DIV) Page 14 of 23

15 8.2 Output Voltage Start-up Profile Figure 13 Output voltage at start-up, Battery model, Vin=90 Vac Figure 14 Output voltage at start-up, Battery model, Vin=265 Vac Page 15 of 23

16 8.3 Load Transient Response (0.2 A to 0.4 A Load Step) Figure 15 Dynamic Load Transient 0.2 A to 0.4 A step load at Vin= 90 Vac CH2: Output Voltage (1V/DIV); CH3: Load Current Figure 16 Dynamic Load Transient 0.2 A to 0.4 A step load at Vin= 265 Vac CH2: Output Voltage (1V/DIV); CH3: Load Current Page 16 of 23

17 8.4 Output Ripple Measurement Ripple Measurement Technique For DC output ripple measurements, a modified oscilloscope test probe must be utilized in order to reduce spurious signals due to pickup. Details of the probe modification are provided in Figure 17 and Figure 18. The 5125BA probe adapter is affixed with two capacitors tied in parallel across the probe tip. The capacitors include one (1) 0.1 µf/50 V ceramic type and one (1) 1.0 µf/50 V aluminum electrolytic. The aluminum electrolytic type capacitor is polarized, so proper polarity across DC outputs must be maintained (see below). Probe Ground Probe Tip Figure 17 Oscilloscope Probe Prepared for Ripple Measurement. (End Cap and Ground Lead Removed) Figure 18 Oscilloscope Probe with Probe Master 5125BA BNC Adapter (Modified with wires for probe ground for ripple measurement, and two parallel decoupling capacitors added). Page 17 of 23

18 8.4.2 Output Voltage Ripple Measurements were made using resistive load. Figure 19: Vin= 90 Vac at full load Figure 20: Vin= 265 Vac at full load Page 18 of 23

19 9 EMI Tests The EMI tests were done at 230Vac & 115V (Line & Neutral), with a 20 Ω resistive load. 9.1 CSPR22B at 230 Vac Figure 21 Conducted EMI, Vin= 230 Vac, 60 Hz line, CSPR22B Limits, NEUTRAL; Output return connected to Artificial hand Figure 22 Conducted EMI, Vin= 230 Vac, 60 Hz line, CSPR22B Limits, LINE; Output return floating Page 19 of 23

20 9.2 CSPR22B at 115 Vac Figure 23 Conducted EMI, Vin= 115V Vac, 60 Hz line, CSPR22B Limits, NEUTRAL, Output return connected to Artificial hand Figure 24 Conducted EMI, Vin= 115V Vac, 60 Hz line, CSPR22B Limits, LINE, Output return connected to Artificial hand Page 20 of 23

21 1-10 Revision History Date Author Revision Description & changes Reviewed February 4, 2004 ME 1.0 Initial release AM/VC Page 21 of 23

22 Notes Page 22 of 23

23 For the latest updates, visit our Web site: reserves the right to make changes to its products at any time to improve reliability or manufacturability. does not assume any liability arising from the use of any device or circuit described herein, nor does it convey any license under its patent rights or the rights of others. The products and applications illustrated herein (including circuits external to the products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to. A complete list of patents may be found at. The PI Logo, TOPSwitch, TinySwitch, LinkSwitch, and EcoSmart are registered trademarks of Power Integrations, Inc. PI Expert and DPA-Switch are trademarks of, Inc. Copyright 2003,, Inc. WORLD HEADQUARTERS NORTH AMERICA - WEST, Inc Hellyer Avenue San Jose, CA USA. Main: Customer Service: Phone: Fax: NORTH AMERICA - EAST & SOUTH AMERICA, Inc. Eastern Area Sales Office 1343 Canton Road, Suite C1 Marietta, GA USA Phone: Fax: EUROPE & AFRICA (Europe) Ltd. Centennial Court Easthampstead Road Bracknell Berkshire RG12 1YQ, United Kingdom Phone: Fax: TAIWAN International Holdings, Inc. 2F, #508, Chung Hsiao E. Rd., Sec. 5, Taipei 105, Taiwan Phone: Fax: CHINA International Holdings, Inc. Rm# 1705, Bao Hua Bldg Hua Qiang Bei Lu Shenzhen Guangdong, Phone: Fax: KOREA International Holdings, Inc. Rm# 402, Handuk Building, Yeoksam-Dong, Kangnam-Gu, Seoul, Korea Phone: Fax: JAPAN, K.K. Keihin-Tatemono 1st Bldg Shin-Yokohama 2- Chome, Kohoku-ku, Yokohama-shi, Kanagawa 222, Japan Phone: Fax: INDIA (Technical Support) Innovatech #1, 8th Main Road Vasanthnagar Bangalore, India Phone: Fax: APPLICATIONS HOTLINE World Wide APPLICATIONS FAX World Wide Page 23 of 23